Locking hinge

ABSTRACT

A locking hinge especially used in a folding shoulder rest for paintball guns. The locking hinge comprises a first hinge plate and a second hinge plate in relative rotation. The first hinge plate has a hinge joint axis, a plurality of symmetric mounting holes, and a counter bore for receiving the locking mechanism. The counter bore in the first hinge plate contains a spring and a locking cylinder. The locking cylinder has a taper on the end directed toward the second hinge plate. The second hinge plate has a relative hinge joint axis, a plurality of tapered circular cavities or notches, and a means for symmetric mounting. The locking mechanism sufficiently aligns with the tapered circular cavities or notches at plurality of predetermined positions thereby preventing rotation of the hinge plates. A minor misalignment between the locking mechanism and tapered circular cavities further provide rigid locking of the hinge plates.

FIELD OF THE INVENTION

[0001] This invention relates to locking hinges especially for use in a folding shoulder rest for paintball guns.

BACKGROUND—DESCRIPTION OF RELATED ART

[0002] Locking hinges presently exist in folding shoulder rests built for real guns. Such shoulder rests are not readily adaptable for use on paintball guns. Paintball gun shoulder rests that exist are only telescopic for arm length. Such a paintball gun shoulder rest presents a problem in that the shoulder rest does not fold, allowing for compact storage or compact use of a paintball gun.

SUMMARY

[0003] The present invention relates to a locking hinge having two rotatable plates. A first hinge plate contains a locking mechanism, which is a spring and a locking cylinder. The locking cylinder has a tapered end directed toward the second hinge plate. A second hinge plate incorporates a tapered circular cavity or notch, which receives the tapered end of the locking cylinder. There is a misalignment of the axis of the locking mechanism and the axis of the tapered circular cavity or notch thereby providing the rigid locking of the hinge plates at predetermined positions. The first and second hinge plates have a symmetrical axis by which mounting holes are located.

[0004] An advantage of the present invention is that the intentional misalignment of the locking mechanism allows for increased part tolerances. The increased of part tolerance allows more economic manufacture of the locking hinge.

[0005] A further advantage of the present invention is the symmetrical axis of mounting. This allows the reverse swing of the locking hinge. The location of the shoulder rest, and any extra components attached to the auxiliary mounting holes, are not changed.

[0006] A next advantage of the present invention is that looseness due to wear of the hinge mating surfaces throughout the hinge life may be significantly reduced by adjusting a connecting bolt that secures the two hinge plates together through the hinge axis.

[0007] Another advantage of the present invention is that the combined misalignment and the tapered edges of the locking mechanism provide continues rigid locking and no maintenance during the life of the locking hinge.

[0008] A yet another advantage of the present invention is that all locking hinge components may be manufactured using only one type of machine.

[0009] A further advantage of the present invention is that it may be used in a variety of manufacturing disciplines including, but not limited to, manufacturing, advertising, military, navy, recreational, marine, automotive, medical, and aerospace. Such disciplines may require locking doors, poles, hatches, and orthopedic devices.

DRAWING FIGURES

[0010]FIG. 1 is an exploded isometric view showing a locking hinge and all components.

[0011]FIG. 2 is a perspective view showing a locking hinge in a open and locked position.

[0012]FIG. 3 is a perspective view showing a locking hinge in a closed and locked position.

[0013]FIG. 4 is a top view showing a locking hinge in an open and locked position.

[0014]FIG. 5 is a sectional view taken along line 5-5 in FIG. 4, showing the locking hinge in an open position and the locking cylinder prior to engagement and a symmetry axis.

[0015]FIG. 6 is a sectional view taken along line 6-6 in FIG. 4, showing the locking hinge in an open position and the locking cylinder prior to engagement and the hinge bolt.

[0016] Corresponding reference characters indicate corresponding parts throughout the figures. The exemplification's set out herein illustrate at least one preferred embodiment of the invention, in one form, and such exemplification's are not to be construed as limiting the scope of the invention in any manner.

REFERENCE NUMERALS IN DRAWING

[0017] REFERENCE NUMBERALS IN DRAWING 10. first hinge plate 11. second hinge plate 12. hinge joint axis 13. spring 14. locking cylinder 15. taper 16. receiving counter bore 17. spring guide hole 18. first hinge mounting holes 19. first hinge mounting arm 20. contact area 21. second mounting holes 22. tapered circular cavity 23. flange 24. push button 25. counter bore 26. symmetry axis 27. auxiliary mounting holes 28. hinge bolt 29. washer 30. nut 31. receiving hole 32. tapered semicircular notch 33. notch axis 34. bolt counter bore 35. first hole 36. axis of locking mechanism 37. a locking hinge 38. circular cavity axis 39. second hole

DESCRIPTION OF THE INVENTION

[0018] Referring now to the drawings, and more particularly FIGS. 1-3, there is shown a locking hinge 37. Generally, a locking hinge 37 includes a hinge joint axis 12, a first hinge plate 10, a second hinge plate 11, a spring 13, a locking cylinder 14 and a push button 24.

[0019] Shown in FIGS. 4, 5 and 6, a first hinge plate 10 has a receiving counter bore 16 which contains a spring 13 and guides locking cylinder 14. One end of spring 13 contacts the bottom of counter bore 16. The other end of spring 13 contacts locking cylinder 14 through spring guide hole 17. Counter bore 16 allows locking cylinder 14 free movement along the axis of the locking mechanism 36. First hinge plate 10 has a symmetry axis 26. First hinge mounting holes 18 are equally spaced about the symmetry axis 26.

[0020] As seen in FIGS. 1, 5 and 6, second hinge plate 11 has receiving hole 31 which push button 24 is inserted. Push button 24 stops at the bottom of tapered circular cavity 22 because of flange 23. Tapered circular cavity 22 and tapered semicircular notch 32 have similar tapered walls. Wall taper may range between 10 and 30 degrees. Push button 24 is used to disengage locking cylinder 14 from second hinge plate 11. Assemble hinge bolt 28 through washer 29 and first hole 35, and then recessed in bolt counter bore 34 in first hinge plate 10. Continuing hinge bolt 28 through second hole 39 in second hinge plate 11. Another washer 29 is placed over hinge bolt 28. The entire assembly is held together using nut 30. Nut 30 may be a nylon lock nut, which allows tightness adjustment between the first hinge plat 10 and second hinge plate 11. Contact area 20 is a considerably larger area than the cross sectional area of hinge bolt 28. The area of contact area 20 may be 20 mm squared. The cross sectional area of hinge bolt 38 may be 0.7 mm squared. Contact area 20 is relatively larger, which creates a more stable locking hinge 37.

[0021] Circular cavity axis 38 is not aligned in respect to axis of locking mechanism 36. The axis misalignment may range from 0.1 mm to 0.5 mm. The axis misalignment is a linear distance perpendicular to hinge joint axis 12. The misalignment causes taper 15 of locking cylinder 14 to wedge against tapered circular cavity 22. The wedging action tilts locking cylinder 14 against the wall of receiving counter bore 16. Taper 15 angle may range between 10 and 30 degrees. Notch axis 33 and circular cavity axis 38 are of the same radius from hinge joint axis 12.

[0022] A folded and locked position is shown in FIG. 3, where first hinge plate 10 partially covers tapered circular cavity 22. First hinge plate 10 also partially covers and retains push button 24. Locking cylinder 14 engages tapered semicircular notch 32 in this folded position. Locking hinge 37 is then unfolded by directly pressing on locking cylinder 14. Locking cylinder 14 lies inside or outside the periphery of contact area 20.

[0023]FIG. 5 shows symmetry axis 26. First hinge mounting holes 18 and first hinge mounting arm 19 are symmetric about symmetry axis 26. Second mounting holes 21, counter bore 25 and auxiliary mounting holes 27 are symmetric about symmetry axis 26. Locking hinge 37 may be mounted 180 degrees about symmetry axis 26. A reverse mounted locking hinge 37 provides use for right hand or left hand human.

[0024] In general, many components of this locking hinge would ideally be made of aluminum, plastic or other material that is inexpensive; readily formed and/or machined; and both mechanically and chemically durable. Additionally, such components may be made by any of a variety of appropriate manufacturing methods.

[0025] While this invention has been described as having a preferred design, the present inventrion can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. 

I claim:
 1. A locking hinge used in a folding gun stock for a paintball gun, comprising: a first and second hinge plate which are relatively rotatable about a hinge joint axis and a locking means which prevents further relative movement of said first and second hinge plates at a plurality of predetermined positions, said locking means is in the form of a cylinder which the axis of said cylinder is parallel to said hinge joint axis; a hole or notch provided in both said first and second hinge plates receives said locking means thereby preventing the hinge plates from further rotation about said hinge joint at said predetermined positions, which said locking means may lie within or without the periphery of the plates.
 2. a hinge as claimed in claim 1, wherein said first hinge plate contains a biasing means and said locking means within a hole thereof
 3. a hinge as claimed in claim 2, wherein said biasing means is a compression spring
 4. a hinge as claimed in claim 2, wherein said cylinder has a tapered edge and said hole may be a counter bore
 5. a hinge as claimed in claim 1, wherein said second hinge plate has a plurality of tapered holes or notches for receiving said cylinder which prevent relative rotation of said first and second hinge plates at a plurality of predetermined positions
 6. a hinge as claimed in claim 1, wherein said first and second hinge plates provide a plurality of mounting holes
 7. a hinge as claimed in claim 6, wherein the mounting holes are located about a symmetry axis which allows the reverse swing of said locking hinge
 8. a hinge as claimed in claim 7, wherein said plurality of holes are counter bored allowing attachment of additional devices to said locking hinge through use of auxiliary mounting holes
 9. a hinge as claimed in claim 1, wherein a misalignment of the locking mechanism axis and the receiving hole or notch axis thereby provide rigid locking
 10. a paintball gun folding shoulder rest using a locking hinge, comprising a locking hinge comprising a first and second hinge plates which are respectively rotatable about a hinge joint and a locking means which prevents further relative movements of said first and second hinge plates at a plurality of predetermined positions, said locking means is in the form of a tapered cylinder moved by a bias means a hole or notch provided in both said first and second hinge plates, which is for receiving said locking means thereby preventing the hinge plates from further rotation about said hinge joint at said plurality of predetermined positions
 11. a paintball gun folding shoulder rest as claimed in claim 10, wherein said bias means may be a spring which forces said tapered cylinder toward the second hinge plate at a position in which said locking means will lock said first and second hinge plate at any one of said predetermined positions
 12. a paintball gun folding shoulder rest as claimed in claim 10, wherein said locking means has actuation means for selectively releasing said locking means
 13. a paintball gun folding shoulder rest as claimed in claim 12, wherein said actuation means is in the form of a push button
 14. a paintball gun folding shoulder rest as claimed in claim 13, wherein said push button has a cylindrical shape and a flange
 15. a paintball gun folding shoulder rest as claimed in claim 10, wherein said locking means may have a partial engagement to said hole or notch in said first or second hinge plates at said predetermined positions
 16. a paintball gun folding shoulder rest as claimed in claim 15, wherein said partial engagement provides direct actuation upon said locking means for disengaging from said predetermined positions thereby providing free rotation of said first and second hinge plate. 